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Significant accounting policies.

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Description of risks that arise due to the volume of business transacted with a particular customer. At a minimum, the description informs financial statement users of the general nature of the risk, but excludes "Information about Major Customers" that may be disclosed elsewhere (for instance, segment disclosures).

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The total expense recognized in the period for promotion, public relations, and brand or product advertising.

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Description of timing for satisfying performance obligation in contract with customer. Includes, but is not limited to, as services are rendered, and upon shipment, delivery or completion of service.

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The aggregate total amount of expenses directly related to the marketing or selling of products or services.

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The Company and Summary of Significant Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) Customer	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Significant Accounting Policies [Line Items]
Subscription contracts, typical length	The subscription contracts are generally for 30 days or 12 months in length, billed in advance.
Shipping and handling costs	$ 138,150	$ 152,569	$ 138,679
Advertising and promotional expenses	$ 21,300	$ 24,700	23,200
Minimum
Significant Accounting Policies [Line Items]
Finite-lived intangible asset, useful life (in years)	3 years
Maximum
Significant Accounting Policies [Line Items]
Finite-lived intangible asset, useful life (in years)	10 years
Accounts Receivable \| Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk, customer	No other customers accounted for 10% or greater of the Company's total accounts receivable.
Number of customer \| Customer	0
Accounts Receivable \| Customer Concentration Risk \| Minimum
Significant Accounting Policies [Line Items]
Concentration risk, percentage	10.00%
Accounts Receivable \| Best Buy Inc \| Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk, percentage	34.00%	31.00%
Accounts Receivable \| Amazon \| Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk, percentage	13.00%	13.00%
Accounts Receivable \| Walmart \| Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk, percentage	10.00%
Shipping and Handling
Significant Accounting Policies [Line Items]
Shipping and handling costs	$ 8,700	$ 9,500	$ 8,600
Foreign Exchange Forward \| Maximum
Significant Accounting Policies [Line Items]
Derivative, term of contract (in months)	6 months